Provided is a frame forming structure for use with a frame and a sash of an aluminium-wood combined door/window. The door/window may include at least a door/window frame or a door/window sash frame. The door/window frame or the door/window sash frame is formed by two connecting adjacent profile frame strips by means of an angle forming device and a round tenon rod on adjacent connecting end surfaces. Symmetric U-shaped notches for positioning the angle forming device and symmetric round tenon rod holes are processed on the connecting end surfaces of the two adjacent profile frame strips. A round tenon is used for positioning and inserted into the symmetric round tenon rod holes. A assembly-type the angle forming device is fixed the two adjacent profile frame strips. The disclosure has characteristics of increasing connecting strength of an angle portion and sealing performance after angle formation, improving convenience of frame formation.